Selective oxidation catalysts for halogenated organics

Abstract

The invention relates to a process and a catalyst composition for the destruction of volatile organic compounds (VOCs). The process includes the step of contacting the VOCs with an oxygen-containing gas in the presence of a catalyst which is a metal-exchanged, metal-impregnated aluminosilicate zeolite with at least one exchanged metal in the zeolite being selected from the group consisting of Ti, V, Cr, Co, Ni, Cu, Fe, Mo, Mn, Pd, and Pt, and at least one impregnated metal in the zeolite being selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Pd and Pt, and wherein the difference between the exchanged metal and the impregnated metal varies the temperature necessary to promote oxidation of the compounds and for a contact time sufficient to oxidize the compounds. The process reaction temperature can vary from about 100° C. to about 650° C. and the contact time can vary from about 0.01 to 20 seconds. Preferredly, the reaction temperature is from about 150° C. to about 450° C. and the contact time is from about 0.1 to 1.0 seconds. The CO/CO 2 ratio and the Cl 2 /HCl ratio in the gaseous effluent can be varied through selection of at least two impregnating metals with at least one exchanged metal in the aluminosilicate zeolite or by the use of at least one impregnating metal with at least two exchanged metals in the aluminosilicate zeolite.

What is claimed is: 
     
       1. A process for the destruction of halogenated organic compounds comprising the step of contacting the compounds with an oxygen-containing gas in the presence of a catalyst comprising: (a) a metal-exchanged, metal-impregnated aluminosilicate zeolite wherein (i) at least one exchanged metal in the zeolite is selected from the group consisting of Ti, V, Cr, Co, Ni, Cu, Fe, Mo, Mn, Pd, and Pt, and   (ii) at least one impregnated metal in the zeolite is selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Pd and Pt, and wherein the difference between the exchanged metal and the impregnated metal varies a temperature necessary to promote oxidation of the compounds and for a contact time sufficient to oxidize the compounds.       
     
     
       2. The process of claim 1 wherein the temperature is from about 100° C. to about 650° C. and the contact time is from about 0.01 to 20 seconds. 
     
     
       3. The process of claim 2 wherein the temperature is from about 150° C. to about 450° C. and the contact time is from about 0.1 to 1.0 seconds. 
     
     
       4. The process of claim 1 wherein the catalyst contains a support. 
     
     
       5. The process of claim 4 wherein the support is selected from the group consisting of alumina, aluminum oxide, silica, silicates, silica-aluminas, titanias, zeolites, polymeric supports, carbon and cordierite. 
     
     
       6. The process of claim 5 wherein the support is a honeycomb support. 
     
     
       7. The process of claim 1 wherein the catalyst contains a binder. 
     
     
       8. The process of claim 7 wherein the binder is selected from the group consisting of alumina, silica, alumina-silica, cordierite, titania, zirconia, vanadia, zeolites and other inorganic materials used as binding agents. 
     
     
       9. The process of claim 1 wherein the catalyst comprises from about 0.2 wt. % to 12 wt. % of at least one impregnating metal and from about 10 wt. % to 95 wt. % of the metal-exchanged aluminosilicate zeolite. 
     
     
       10. A process for the destruction of halogenated organic compounds comprising the step of contacting the compounds with an oxygen-containing gas in the presence of a catalyst comprising: (a) a metal-exchanged, metal-impregnated aluminosilicate zeolite wherein (i) at least one exchanged metal in the zeolite is selected from the group consisting of Ti, V, Cr, Co, Ni, Cu, Fe, Mo, Mn, Pd, and Pt, and   (ii) at least one impregnated metal in the zeolite is selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Pd and Pt, and wherein the difference between the exchanged metal and the impregnated metal varies a temperature necessary to promote oxidation of the compounds and for a contact time of about 0.2 to 1.0 seconds, sufficient to oxidize the compounds, and to permit the selective modification of the CO/CO 2  ratio and the Cl 2  /HCl ratio of the process without changing the temperature by the selective incorporation of at least two exchanged metals with at least one impregnated metal in the zeolite or the selective incorporation of at least one exchanged metal with at least two impregnated metals in the zeolite.       
     
     
       11. The process of claim 10 wherein the temperature is from about 100° C. to about 650° C. and the contact time is from about 0.01 to 20 seconds. 
     
     
       12. The process of claim 11 wherein the temperature is from about 150° C. to about 450° C. and the contact time is from about 0.1 to 1.0 seconds. 
     
     
       13. The process of claim 10 wherein the catalyst contains a support. 
     
     
       14. The process of claim 13 wherein the support is selected from the group consisting of alumina, aluminum oxide, silica, silicates, silica-aluminas, titanias, zeolites, polymeric supports, carbon and cordierite. 
     
     
       15. The process of claim 14 wherein the support is a honeycomb support. 
     
     
       16. The process of claim 10 wherein the catalyst contains a binder. 
     
     
       17. The process of claim 16 wherein the binder is selected from the group consisting of alumina, silica, alumina-silica, cordierite, titania, zirconia, vanadia, zeolites and other inorganic materials used as binding agents. 
     
     
       18. The process of claim 10 wherein the catalyst comprises from about 0.2 wt. % to 12 wt. % of at least one impregnating metal and from about 10 wt. % to 95 wt. % of the metal-exchanged aluminosilicate zeolite.